Proper airflow is a critical component to assure maximum efficiency in forced-air ducted air conditioning (AC) systems. The Department of Energy sponsored Energy Star Survey determined that more than 50% of air-conditioning installations have low airflow. Low airflow reduces system efficiency (SEER), increases energy costs, results excessive maintenance and repair costs, and leads to premature failure of equipment.
Current methodology to measure and establish proper airflow is problematic and unreliable. Methods known in the art, such as placing an air velocity meter inside an AC duct and then estimating the cross-sectional area of the duct, are far too complex and prone to inaccuracy for field technician charged with effectively diagnosing problems with AC systems. More accurate and precise methods of measuring and establishing proper airflow typically require extensive technician training, and expensive instrumentation and installation costs.
One example of a known method of measuring airflow in HVAC systems includes the use of “flow hoods.” A flow hood typically consists of a large housing having a known area and an air velocity sensor placed therein. The hood is then placed over an intake grill or return grill of a given ducted AC system, and the air velocity is measured. The clear downside to these flow hoods is that the large housing often renders the flow hood useless in buildings where the grills are too close to other structural elements and therefore the flow hood, while accurate, simply cannot be used.
Other examples of known methods for measuring HVAC airflow include temperature-based methods. Typically, one first turns on the heating element within the system and then measures the temperature of the air going into the heater and the temperature of the air leaving the heater. Then, a series of calculations are carried out, resulting in a determination of the airflow velocity. However, this indirect method of calculating airflow velocity can be very imprecise and inaccurate due to the stratification of the temperature gradient across the system and therefore is not effective in diagnosing problems within the HVAC system, whether up-stream or down-stream from the air handling unit.
Known means for monitoring the performance and efficiency of an HVAC system have severe limitations. Typical thermostats known in the art do not monitor the actual airflow conditions in its attendant HVAC system. Rather, they simply measure the temperature of the room to be cooled/heated and provide a feedback-based switching system for the HVAC system. While some of these thermostats have the ability to inform the user whether a filter change is needed, this indication is usually based solely on the length of operation of the HVAC system between filter changes and does not take into account the actual airflow conditions within the system.
Consequently, there is a marked need in the art for an easy-to-operate, cost-effective, integrated system and method for sensing, measuring, and monitoring the airflow conditions within an HVAC system.